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keycard-redeem
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check overflows and reset amount before transfer

This commit is contained in:
Andrea Franz 2020-02-21 16:57:23 +01:00
parent 42feca196c
commit 54a98a773c
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GPG Key ID: 4F0D2F2D9DE7F29D
1 changed files with 14 additions and 7 deletions
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21
contracts/GiftBucket.sol
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@ -66,6 +66,8 @@ contract GiftBucket {
function availableSupply() public returns(uint256) { function availableSupply() public returns(uint256) {
uint256 _totalSupply = this.totalSupply(); uint256 _totalSupply = this.totalSupply();
require(_totalSupply >= redeemableSupply, "redeemableSupply is greater than redeemableSupply");
return _totalSupply - redeemableSupply; return _totalSupply - redeemableSupply;
} }
@ -82,24 +84,29 @@ contract GiftBucket {
gift.amount = amount; gift.amount = amount;
gift.code = code; gift.code = code;
require(redeemableSupply + amount > redeemableSupply, "addition overflow");
redeemableSupply += amount; redeemableSupply += amount;
} }
function redeem(Redeem calldata _redeem, bytes calldata sig) external { function redeem(Redeem calldata _redeem, bytes calldata sig) external {
require(block.timestamp < expirationTime, "expired gift"); require(block.timestamp < expirationTime, "expired gift");
bool signedByKeycard = verify(_redeem, sig); Gift storage gift = gifts[_redeem.keycard];
require(signedByKeycard, "wrong keycard sig");
Gift memory gift = gifts[_redeem.keycard];
require(gift.amount > 0, "not found"); require(gift.amount > 0, "not found");
bool signedByKeycard = verifySig(_redeem, sig);
require(signedByKeycard, "wrong keycard sig");
bytes32 codeHash = keccak256(abi.encodePacked(_redeem.code)); bytes32 codeHash = keccak256(abi.encodePacked(_redeem.code));
require(codeHash == gift.code, "invalid code"); require(codeHash == gift.code, "invalid code");
uint256 amount = gift.amount;
require(redeemableSupply >= amount, "not enough redeemable supply");
redeemableSupply -= gift.amount; gift.amount = 0;
tokenContract.transfer(_redeem.receiver, gift.amount); redeemableSupply -= amount;
tokenContract.transfer(_redeem.receiver, amount);
} }
function kill() external onlyOwner { function kill() external onlyOwner {
@ -120,7 +127,7 @@ contract GiftBucket {
)); ));
} }
function verify(Redeem memory _redeem, bytes memory sig) internal view returns(bool) { function verifySig(Redeem memory _redeem, bytes memory sig) internal view returns(bool) {
require(sig.length == 65, "bad signature length"); require(sig.length == 65, "bad signature length");
bytes32 r; bytes32 r;